Method of making inflatable life raft

ABSTRACT

A method of making an inflatable raft comprises forming an annular inflatable member of the raft from an elongate rectangular blank of gas impervious yieldable resilient material. The rectangular blank of material is measured and marked to locate a plurality of longitudinally spaced apart fold areas along one surface thereof, and the blank is then cut along its longitudinal center line to form two identical panels. The longitudinal edges of the panels are secured together in lapped sealing relation to form the panels into a tube with the marked fold areas thereof being disposed exteriorly. The ends of the tube are then secured together in telescoping sealed relation to form the tube into an annular hollow member, the fold areas being disposed along the inner external peripheral surface of the annular member. The fold areas are then folded inwardly and are secured in inward folded relation by an elongate fold engaging tape which is provided with a plurality of fold engaging elements that extend into the fold engaging areas. Narrow covering tapes encircle the annular member and cover the fold areas. The annular member when inflated, defines a polygon, each side of which extends between adjacent folds.

United States Patent 1191 Jones METHOD OF MAKING INFLATABLE LIFE 73]Assignee: Rubber Dynamics Corporation,

Armstrong. Iowa 221 Filed: Apr. 25. 1974 211 Appl. No.: 464,204

[52] U.S. C1. 156/145; 9/2 A; 156/198; 156/203; 156/204; 156/218;156/227 [51] Int. Cl. A63B 39/00 [58] Field of Search 156/198. 226. 227.145. 156/147. 203. 218. 204. 205. 474; 9/2 A. 11 A. 330

[56] References Cited UNITED STATES PATENTS 1.392.533 10/1921 Smyth 9/2A 2.456086 l2/l948 Schwall 1. 1 9/2 A 2.717.849 9/1955 Rempel et al 9/2A X 1.839.440 6/1958 Pfeiffer et al [56/198 X 3.048.514 8/1962 Benteleet al 156/204 X 3.774.566 11/1973 Moore 9/2 A X Primary Emm/ner-CharlesE. Van Horn Ass/5mm E.\(u11111erDavid A. Simmons Almraey. Agent. orF1r//1Williamson. Bains & Moore 14 1 Nov. 11, 1975 [57] ABSTRACT Amethod of making an inflatable raft comprises forming an annularinflatable member of the raft from an elongate rectangular blank of gasimpervious yieldable resilient material. The rectangular blank ofmaterial is measured and marked to locate a plurality of longitudinallyspaced apart fold areas along one surface thereof. and the blank is thencut along its longitudinal center line to form two identical panels. Thelongitudinal edges of the panels are secured together in lapped sealingrelation to form the panels into a tube with the marked fold areasthereof being disposed exteriorly. The ends of the tube are then securedtogether in telescoping sealed relation to form the tube into an annular hollow member. the fold areas being disposed along the innerexternal peripheral surface of the annular member. The fold areas arethen folded inwardly and are secured in inward folded relation by anclongate fold engaging tape which is provided with a plu rality of foldengaging elements that extend into the fold engaging areas. Narrowcovering tapes encircle the annular member and cover the fold areas. Theannular member when inflated. defines a polygon. each side of whichextends between adjacent folds.

2 Claims. 6 Drawing Figures U.S. Patent Nov. 11, 1975 METHOD OF MAKINGINFLATABLE LIFE RAFT SUMMARY OF THE INVENTION This invention relates toinflatable rafts, and more specifically to a method of making aninflatable raft.

Most inflatable rafts are formed of an inflatable annular tube whichforms the periphery or sides of the raft. A flexible bottom member issecured to the annular tube and forms the floor of the raft. In themanufacture of these prior art inflatable rafts, the annular tube isformed from a plurality of tubular sections which are secured togetherin sealing relation. Certain of the tubular sections, in these prior artdevices, are of arcuate configuration, when inflated. Therefore, inorder to make such an arcuate tubular section, the pieces of materialfrom which each tubular section is made, must be cut so that when thepieces of material are secured together to form a tubular section, itwill assume an arcuate shape. It has been found that inflatable raftsmanufactured according to such a method results in a substantial loss ofmaterial since the pieces of material from which these arcuate tubularsections are formed must be cut into nonrectangular configuration.Furthermore, since the annular member of these prior art inflatablerafts are comprised of a plurality of sections which are sealinglyjoined together, each joined seam represents a potential area in which aleak may occur.

It is therefore a general object of this invention to provide a uniquemethod of forming the inflatable annular member of an inflatable raftfrom a rectangular blank of material which has minimum of sealed seams.In carrying out this method, the blank is measured and marked to locatea number of fold areas along one surface of the blank and the blank iscut along its longitudinal center line to form two identical panels. Thelongitudinal edges of the panels are then secured together to fonn atube and the ends of the tube are secured together to then form the tubeinto an annular member. The fold areas are disposed along the innerexternal surface of the annular member and the fold areas are foldedinwardly and are secured in place by an elongate tape. When the annularmember is inflated, the annular member defines a polygon, preferably anoctagon, which is not only safer in construction than the prior artinflatable members, but which may be manufactured in a more economicalmanner than the manufacture of prior art rafts.

These and other objects and advantages of this invention will more fullyappear from the following description made in connection with theaccompanying drawings wherein like reference characters refer to thesame or similar parts throughout the several views.

DESCRIPTION OF THE FIGURES OF THE DRAWINGS FIG. 1 is a perspective viewof the life raft made in accordance with the present invention;

FIG. 2 is a plan view of the blank used in the manufacture of theinflatable annular member of the raft; and with the fold areas markedthereon; and after the blank longitudinal cut;

1 FIG. 3 is a perspective view illustrating the formation Qof a tubefrom the panels;

FIG. 4 is a perspective view of the fold engaging tape;

FIG. 5 is a plan view of the inflatable annular member illustrating themanner in which the fold engaging ltape is applied;

FIG. 6 is an enlarged fragmentary cross-sectional view illustrating themanner in which the fold engaging portions or elements of the foldengaging tape engage the inward folds of the annular member.

DETAILED DESCRIPTION OF THE PREFERRRED EMBODIMENTS OF THE INVENTIONReferring now to FIG. 1, it will be seen that one embodiment of aninflatable raft, designated generally by the numeral 10 is there shown.The raft I0 is comprised of an inflatable annular member 11 to which issecured a bottom sheet or floor 12. The raft is preferably formed of ayieldable resilient material, preferably neoprene rubber, although anysuitable air impervious flexible resilient material may also be used.The inflatable annular member 11 is constructed from an elongaterectangular blank of material 13 of predetermined length and width. Itwill be appreciated that the length and width of the blank will bedependent upon the size of the inflatable annular member 11. The blank13 includes opposed longitudinal edges 14 and opposed end edges 15.

After the blank I3 has been cut from a strip of material, a template(not shown) is applied to the blank to properly locate the plurality oflongitudinally spaced apart fold areas 16. The fold areas 16 are markedon one surface of the blank by a suitable marking crayon or pencil, andit will be noted that the fold areas are defined by generally diamondshaped patterns which are truncated at their ends. It will also be notedthat the annular member 11, illustrated in FIG. I, is of octagonalconfiguration, and accordingly, the blank 13 has eight substantiallyidentical fold areas 16 marked thereon.

After the fold areas have been located and marked, the blank 13 is cutalong its longitudinal center line to form the blank into two identicalpanels 130. The panels 13a are then formed into an elongate tube byoverlapping each longitudinal edge of one panel with a longitudinal edgeof the other panel. These lapped edges are secured together with anelongate inner tape or strip 17 and an elongate outer tape or strip 18.The inner and outer strips of tape each have one surface thereof coatedwith a suitable adhesive and the tapes are formed of a suitable air andwater impervious material. When the tube 19 is formed by securing thelongitudinal edges of the panels together in lapped relation, thepatterns defining the fold areas 16 will be disposed on the exteriorsurface of the tube.

Thereafter, the respective ends of the tube are urged into telescopinglapped relation, as best seen in FIG. 5, and these lapped ends are gluedtogether to form a sealed lapped joint 20 thereat. It is pointed outthat when the tube 19 is formed into an annular member I l, as shown inFIG. 5, the patterns defining the fold areas 16 will be disposed on theinner, external surface of the annular member.

The fold areas are then tucked or folded inwardly so that each fold areaforms an inward fold 21 which defines inwardly tucked or folded surfaces21a. In this respect, the inwardly tucked or folded surfaces 21a will befolded or tucked inwardly so that only the periphery of the fold patternwill be disposed externally.

Means are then applied to the annular member to secure the inwardlyfolded surfaces 210 of each fold in inwardly folded relation, and thismeans includes an elongate fold-engaging tape 22. This fold-engagingtape 22 has an adhesive inner surface 23 and is of the lengthcorresponding to the inner external periphery of the annular member 11,as best seen in H6. 5. The elongate strip of fold-engaging tape 22 has aplurality of longitudinally spaced apart reinforcing tabs secured to thenonadhesive surface thereof. each of these tabs 24 also being formed ofthe same material of which the fold-engaging tape 22 is formed. Thereinforcing tabs 24 have the same width as the fold-engaging tape 22 andthe spacing between the tabs corresponds generally to the spacingbetween adjacent inwardly extending folds 21. The fold-engaging tape isprovided with a plurality of U-shaped fold-engaging elements or portions25 each being secured to the fold-engaging tape at one of thereinforcing tabs 24 by suitable stitching 26. The U-shaped fold-engagingtape elements 25 each has an adhesive surface 27 and each tape element25 is merely a short strip or piece of tape material of the type used toform the fold-engaging tape 22.

When the fold-engaging tape 22 is applied to the inner externalperipheral surface of the annular member 11, each of the U-shapedfold-engaging elements 25 will be urged into a fold 21 and will adhereto the inwardly disposed fold surfaces 210 of each fold. Thus theinwardly folded surfaces 21a will be secured in inwardly folded relationand only the lines defining the fold areas will define the exterior foldlines of each fold 2i.

Thereafter, a plurality of elongate cover strips or tapes 28 will beapplied to the annular member each encircling and covering one of thefolds 21. Each tape 28 has an adhesive surface, and it is pointed outthat each tape strip l7, I8, 22, 25 and 28 are preferably formed of thesame material and each may be cut from an elongate roll of such tapematerial. Thus, all of the tape components used in the manufacture ofthe annular member will be of uniform width and will be formed of a gasand water impervious material.

After the cover tapes 28 are applied to the annular member to encircleand cover the fold areas, the floor l2 will be secured to the annularmember by a suitable glue, tape or the like, the floor being formed of aflexible, yieldable water impervious material. The inflatable raft mayalso be provided with an inflatable tubular arch which is secured to theannular member 11, and when inflated, forms a support for a flexiblecover or canopy. These cover supports are also formed in the identicalmanner except that the ends of the tubular arch are not secured togetherbut are sealingly secured to the annular member.

When the inflatable raft is inflated, the annular member 11 will assumethe configuration of a polygon. In the embodiment shown, the annularmember comprises an octagon although other polygonal shapes may also beutilized. Each side of the polygon is defined by those portions of theannular member located between the fold lines. However, the annularmember 11 has only three joints or seams, two of which are defined bythe seals between the lapped longitudinal edges, and the other beingfonned by the lapped sealed ends of the tube. Thus, applicant hasprovided an annular member in which the potential danger of leakage atseals has been substantially reduced because of the reduction in thenumber of sealed joints. lt is also noted that applicant, by utilizingthe present method has constructed a geometrical annular member from apair of panels formed from a single blank of material, therebyminimizing the loss of material normally experienced with typical priorart methods.

It will therefore be seen that applicants unique novel method ofmanufacturing inflatable rafts not only permits economic production ofsuch inflatable rafts, but also provides a safer reliable raft than anyheretofore known methods.

What is claimed is:

l. A method of making an inflatable life raft comprised of an inflatabletubular annular member and a bottom member, said method including:

forming the inflatable annular member from a single elongate rectangularblank of gas-impervious flexible, yieldable resilient material,measuring, locating and marking a plurality of longitudinally spacedapart generally diamond-shaped fold areas on said blank, said fold areasbeing of identical size and shape and being equally spaced apart,cutting said blank along its longitudinal center line to form the blankinto a pair of identical panels,

securing each longitudinal edge of one panel to a longitudinal edge ofthe other panel in sealing relation to form the panels into a tube, themarked fold areas of the tube being disposed exteriorly,

securing the ends of the tube together in lapped sealed relation to formthe tube into an annular hollow member, said fold areas being disposedalong the inner external peripheral surface of the annular member,

folding the fold areas inwardly, each fold area including inwardlyextending fold surfaces,

securing an elongate narrow fold-engaging tape to the inner externalperipheral surface of the annular member, said fold-engaging tape havinga plurality of longitudinally spaced apart U-shaped fold engagingelements secured thereto, the spacing between the fold engaging elementscorresponding to the spacing between said fold areas, said foldengagingelements having the same width dimension as the fold-engaging tape, eachfold-engaging element extending into each fold area and being secured tothe fold surfaces thereof to retain each fold in inwardly foldedrelation, said fold-engaging tape extending throughout the entireperipheral surface of said annular member,

applying a plurality of spaced apart narrow cover tapes to the annularmember, each cover tape having a width dimension corresponding to thewidth dimension of the fold-engaging tape, each tape encircling saidannular member at one of said folds to cover the transverse inward foldline defined by the fold whereby said annular member when inflateddefines a polygon, each side of which extends between adjacent folds,

securing a flexible water impervious bottom member to said annularmember in sealed relation there with.

2. The method as defined in claim 1 wherein said annular member haseight inward folds and thereby defines an octagon.

1. A METHOD OF MAKING AN INFLATABLE LIFE RAFT COMPRISED OF AN INFLATABLE TUBULAR ANNULAR MEMBER AND A BOTTOM MEMBER, SAID METHOD INCLUDING: FORMOING THE INFLATABLE ANULAR MEMBER FROM A SINGLE ELONGATE RECTANGULAR BLANK OF GAS-IMPERVIOUS FLEXIBLE, YIELDABLE RESILIENT MATERIAL, MEASURING, LOCATING AND MAKING A PLURALITY OF LONGITUDINALY SPACED APART GENERALLY DIAMOND-SHAPED FOLD AREAS ON SAID BLANK, SAID FOLD AREAS BEING OF IDENTICAL SIZE AND SHAPED AND BEING EQUALLY SPACED APART, CUTTING SAID BLANK ALONG ITS LONGITUDIAL CENTER LINE TO FORM THE BLANK INTO A PAIR OF IDENTICIAL PANELS, SECURING EACH LONGITUDIAL EDGE OF ONE PANEL TO A LONGITUDINAL EDGE OF THE OTHER PANEL SEALING RELTION TO FORM THE PANELS INTO ATUBE, THE MARKED FOLD AREAS OF THE TUBE BEING DISPOSED EXTERIORILY, SECURING THE ENDS OF THE TUBE TOGETHER IN LAPPED SEALED RELATION TO FORM THE TUBE AN ANNULAR HOLLOW MEMBER, SAID FOLD AREAS BEING DISPOSED ALONG THE INNER EXTERNAL PERIPHERAL SURFACE OF THE ANNULAR MEMBER, FOLDING TO FOLD AREAS INWARDLY, EACH FOLD AREA INCLUDING INWARDLY EXTENDING SURFACES, SECURING AN ELONGATED NARROW FOLD-ENGAGING TAPE TO THE INNER EXTERNAL PERIPHERAL SURFACE OF THE ANNULAR MEMBER, SAID FOLD-ENGAGING TAPE HAVING A PLURALITY OF LONGITUDIALLY SPACED APART U-SHAPED FOLD ENGAGING ELEMENTS SECURED THERETO,THE SPACING BETWEN THE FOLD ENGAGING ELEMENTS CORRESPONDING TO THE SPACING BETWEEN SAID FOLD AREAS, SAID FOLD/ENGAGING ELEMENTS HAVING THE SAME WIDTH DIMENSION AS THE FOLD-ENGAGING TAPE, EACH FOLD-ENGAGING ELEMENTS EXTENDING INTO EACH FOLD AREA AND BEING SECURED TO THE FOLD SURFACES THEREOF TO RETAIN EACH FOLD IN INWARDLY FOLDED RELATION, SAID FOLD-ENGAGING TAPE EXTENDING THROUGHOUT THE ENTIRE PERIPHERAL SURFACE OF SAID ANNULAR MEMBER, APPLYING A PLURALITY OF SPACED APAR NARROW COVER TAPES TO THE ANNULAR MENBER, EACH COVER TAPE HAVING A WIDTH DIMENSION CORRESPONDING TO THE DIMENSION OF THE FOLD-ENGAGING TAPE, EACH TAPE ENCIRCULING SAID ANNULAR MEMBER AT ONE OF SAID FOLDS TO COVER THE TRANSVERSE INWARD FOLD LINE DEFINED BY THE FOLD WHEREBY SAID ANNULAR MEMBER WHEN INFLATED DEFINES A POLYGON, ACH SIDE OF WHICH EXTENDS BETWEEN ADJACENT FOLDS, SECURING A FLEXIBLE WATER IMPERVIOUS MEMBER TO SAID ANNULAR MEMBER IN SEALED RELATION THEREWITH.
 2. The method as defined in claim 1 wherein said annular member has eight inward folds and thereby defines an octagon. 